1. Field of the Invention
The present invention is related generally to prosthetic devices and more specifically to a prosthetic device for use as a temporary substitute for a person's lower leg.
2. Description of the Prior Art
When a person suffers a severe traumatic injury to an ankle, foot, or lower leg, he or she usually cannot use the leg for an extended period of time while the injury heals. To be ambulatory during the healing process, some temporary substitute structural device has to be used to support the person's weight that is normally supported by the leg. The conventional and familiar crutch is still the most common such device, and, in many ways, it is still very practical where the injured person just needs to move from one place to another. However, such ordinary crutches occupy the person's hands and arms for manipulating the crutches and for providing needed stability. Therefore, in situations where the person desires to use his or her hands for other purposes while standing or moving around, such as to carry objects or to perform occupational tasks that require the use of hands while standing or walking, conventional crutches are more of a hindrance than a help. Conventional crutches are also usually used in such a manner that they are a complete substitute for the entire leg, even if only the lower leg, ankle, or foot is injured. Therefore, none of a person's weight is borne by any part of the leg, and the natural result is atrophy of the muscles and tissues in the leg.
There have been several prosthetic devices developed that help support the injured person's body weight to improve mobility and comfort over the use of conventional crutches. For example, the U.S. Pat. No. 2,778,370, issued to W. Chamblee, discloses a padded knee support attached to a conventional crutch. Similarly, the U.S. Pat. No. 4,141,375, issued to L. Tykwinski, extended the support for the lower leg and substituted a cane for the crutch. However, neither one of those devices provided a replacement for a crutch or cane that would be stable and secure enough to free both the person's hands for doing other things and also versatile enough to be convenient and comfortable to use for extended period in a wide range of common day-to-day activities, from standing and walking to driving or riding in vehicles to sitting and resting.
The U.S. Pat. No. 4,254,948, issued to E. Jacobs, is even more cumbersome in that it provides a heavy and somewhat complex crank and drive wheel as a substitute for a person's dangling lower leg, which further aggravates the atrophy problem. Both the U.S. Pat. No. 4,924,894, issued to M. Martinez, and U.S. Pat. No. 875,482, issued to W. Wyatt, disclose artificial limbs for amputees, but they really do not accommodate the needs of a temporary prosthetic device where the lower leg is injured and needs time to heal, but is not amputated.
Consequently, despite the above-described developments, there still remains a need for an improved temporary prosthetic device that is more secure, more stable, more versatile, and more comfortable, while it supports a person's injured lower leg in a nonweight-bearing position and while acting as a replacement for bearing the weight of a person's body while standing, walking, and performing routine tasks in situations where the person needs to have his or her hands relatively free to use for other activities.